This invention relates to the field of detecting and measuring bioluminescence.
Specifically the present invention relates to in situ measurements of bioluminescence intensity in the ocean and other bodies of water. Bioluminescence is one measure of the number and type of organisms in water, which is helpful in understanding population dynamics and certain sound transmission characteristics of water.
Bioluminescence in aquatic environments comes from a wide variety of sources. Tett and Kelly (Oceanogr. Mar. Biol. Ann. Rev, 1973, p 89-173) gives a detailed review of the physics of the measurements, and a phyletic review. Many different species, belonging to most of the phyla exhibit bioluminescence, including Bacteria, Dinoflagellates, Radiolaria, Hydrozoa, Siphonophora, Scyphozoa, Anthozoa, Ctenophora, Polychaeta, Lamellibrachiata, Cephalopoda, Crustacea, Urochordata and Actinopterygii. Studies indicate that these organisms use bioluminescence for a great variety of vital functions. It is an important mechanism for understanding physiological processes. Work has shown that certain species can be identified on the basis of their bioluminescence. Clearly it is one of the commonest radiative processes of organisms as well as one of the most complex. As such, a considerable body of research has accumulated; in fact there is a Journal of Bioluminescence and Chemiluminescence.
Beginning in the 1940""s, instrumentation for quantitative measurements of bioluminescence was developed in several countries. Yentsch and Yentsch (Oceanogr. Maar. Biol. Ann. Rev, 1984, p 55-98), and Gitelson and Levin (Jour Bioluminescence and Chemiluminescence, 1989, p 555-562) describe some of the technology. A more recent paper by Case et al, (Naval Research Reviews, Two 1993, p 31-41) gives a good overview and bibliography. Also, there are several U.S. patents describing techniques and instrumentation for observing bioluminescence. See for example:
U.S. Pat. No. 4,563,331 to Losee and Lapota, xe2x80x9cSystem for measuring bioluminescence flash kineticsxe2x80x9d
U.S. Pat. No. 4,689,305 to Stiffey, Blank and Loeb, xe2x80x9cSolid-state photometer circuitxe2x80x9d
U.S. Pat. No. 4,978,854 to Lapota, Mastny, Copeland, xe2x80x9cBioluminescent detectorxe2x80x9d
U.S. Pat. No. 5,264,906 to Fever, Case, Widder, Bernstein, Lowenstine, xe2x80x9cBiolumescence bathyphotometerxe2x80x9d
U.S. Pat. No. 5,554,035 to Gooch, xe2x80x9cBioluminescent algae in light bulb shaped viewing devicexe2x80x9d
U.S. Pat. No. 5,565,360 to Lapota, Mastny, Copeland, Rosenberger, xe2x80x9cBiolumescent bioassay systemxe2x80x9d
The foregoing instrumentation literature and patents describe tailored systems for fairly specific applications, such as laboratory apparatus to study isolated organisms, or determination of organism response to certain physical or chemical stimulus.
The specificity of the foregoing research objectives overlooks the more flexible observation strategies available in accordance with the present invention which utilizes a suite of small, inexpensive, stable, robust building blocks to make, in concert with other sensors, practical synoptic observations of bioluminescence at ocean fronts, where differing water masses meet.
Accordingly, the present invention provides an economical underway bioluminescence detector that can be used for vertical profiles, horizontal profiles at a fixed depth, or in a vertically undulating mode. The detector is compact and can be attached to a towed or autonomous underwater vehicle (AUV). The vehicle""s motion causes water to flush through a grid in the detector housing to generate the requisite turbulence within the instrument for stimulation of luminescent organisms, which provides a measurement of bioluminescence. The detector can also be used for moored (stationary) applications.
In a preferred embodiment of the invention a submersible bioluminescence detector system is comprised of a housing having an inlet port and an outlet port and a grid disposed at the inlet port in the path of water entering the inlet port to excite organisms in the water to exhibit bioluminescence. The bioluminescence is detected by a photodetector disposed in an hermetically sealed optically clear envelope facing the grid. The biodetector generates a first bioluminescence electrical signal. An analog or digital circuit samples, integrates and amplifies the electrical signal and transmits the signal to a host computer for further processing and display.